Self-supporting reactive hot-melt adhesive element

A reactive hot-melt adhesive element comprising:

• from 0.5 to 30% w/w. of at least one isocyanate;
• from 20 to 90% w/w of at least one isocyanate-reactive polymer and/or resin;
• from 0 to 20% w/w of at least one isocyanate-reactive, mono-functional additive;
• from 0 to 60% w/w of at least one non-isocyanate-reactive polymer, wax and/or resin;
• and
• optionally, up to 5% w/w, in particular in amounts of from 0.01 to 5% w/w of a catalyst;
• and
• optionally, up to 25% w/w, in particular in amounts of from 1 to 25% w/w, preferably 5 to 20% w/w of at least one additive for improving heat conductivity and/or sensitivity to radiation induction;
• all amounts being based on the reactive hot-melt adhesive element.

A self-supporting reactive hot-melt adhesive element, especially in the form of a foil, film, strip or reactive adhesive tape, which comprises:

• a reactive one-component hot-melt adhesive which is solid at room-temperature, said reactive one-component hot-melt adhesive comprising:
• (i) about 0.5 to about 30% w/w, based on said reactive hot-melt adhesive element, of at least one aliphatic or aromatic di- or polyisocyanate which is solid or liquid at room-temperature;
• and
• (ii) about 20 to about 90% w/w, based on said reactive hot-melt adhesive element, of at least one isocyanate-reactive polymer and/or resin which is solid at room-temperature and has an average molecular weight of at least 8,000 g/mol, said isocyanate-reactive polymer and/or resin comprising at least two isocyanate-reactive groups or functions per molecule;
• wherein said isocyanate-reactive polymer and/or resin forms a solid matrix at room-temperature, into which said di- or polyisocyanate is embedded in a homogeneous distribution, and wherein the content of free NCO-groups in the reactive hot-melt adhesive element is at least about 0.5% w/w, relative to the reactive hot-melt adhesive element.

A self-supporting reactive hot-melt adhesive element, especially in the form of a foil, film, strip or reactive adhesive tape, which comprises a reactive one-component hot-melt adhesive which is solid at room-temperature, said reactive one-component hot-melt adhesive comprising:

• (i) about 0.5 to about 30% w/w, based on said reactive hot-melt adhesive element, of a mixture of at least two aliphatic and/or aromatic di- and/or polyisocyanates which are solid or liquid at room-temperature, wherein at least one of said di- and/or polyisocyanates is an unsymmetrically substituted di- and/or polyisocyanate comprising isocyanate functions of different reactivity;
• and
• (ii) about 20 to about 90% w/w, based on said reactive hot-melt adhesive element, of at least one isocyanate-reactive polymer and/or resin which is solid at room-temperature and has an average molecular weight of at least 8,000 g/mol, said isocyanate-reactive polymer and/or resin comprising at least two isocyanate-reactive groups or functions per molecule;
• wherein said isocyanate-reactive polymer and/or resin forms a solid matrix at room-temperature, into which said isocyanate mixture is embedded in a homogeneous distribution, and wherein the content of free NCO-groups in the reactive hot-melt adhesive element is at least about 0.5% w/w, relative to the reactive hot-melt adhesive element.

A self-supporting reactive hot-melt adhesive element, especially in the form of a foil, film, strip or reactive adhesive tape, which comprises:

• a reactive one-component hot-melt adhesive which is solid at room-temperature, said reactive one-component hot-melt adhesive comprising:
• (i) about 0.5 to about 30% w/w, based on said reactive hot-melt adhesive element, of a mixture of 4,4′-diisocyanatodiphenylmethane and 2,4′-diisocyanatodiphenylmethane, preferably with a content of 2,4′-diisocyanatodiphenylmethane exceeding 20% w/w relative to said mixture;
• and
• (ii) about 20 to about 90% w/w, based on said reactive hot-melt adhesive element, of at least one isocyanate-reactive polymer and/or resin which is solid at room-temperature and has an average molecular weight of at least 8,000 g/mol, said isocyanate-reactive polymer and/or resin comprising at least two isocyanate-reactive groups or functions per molecule;
• wherein said isocyanate-reactive polymer and/or resin forms a solid matrix at room-temperature, into which said isocyanate mixture is embedded in a homogeneous distribution, and wherein the content of free NCO-groups in the reactive hot-melt adhesive element is at least about 0.5% w/w, relative to the reactive hot-melt adhesive element.

A self-supporting reactive hot-melt adhesive element, especially in the form of a foil, film, strip or reactive adhesive tape and having a layer thickness in the range of from about 10 μm to about 1,000 μm, said self-supporting reactive hot-melt adhesive element comprising:

• a reactive one-component hot-melt adhesive which is solid at room-temperature which comprises:
• about 0.5 to about 30% w/w of at least one isocyanate which is solid or liquid at room-temperature;
• about 20 to about 90% w/w of at least one isocyanate-reactive polymer and/or resin which is solid at room-temperature;
• optionally, up to about 20% w/w of at least one mono-functional additive;
• optionally, up to about 60% w/w of at least one non-isocyanate-reactive polymer, wax and/or resin;
• optionally, up to about 5% w/w of at least one catalyst;
• optionally, up to about 25% w/w of at least one additive for improving heat conductivity and/or sensitivity to radiation induction;
• all amounts being based on said reactive hot-melt adhesive element,
• wherein said isocyanate-reactive polymer and/or resin forms a solid matrix at room-temperature, into which said isocyanate is embedded in a homogeneous distribution and wherein the content of free NCO-groups in the reactive hot-melt adhesive element is at least about 0.5% w/w, in particular at least about 1% w/w, preferably at least about 1.5% w/w, especially preferably at least about 2% w/w, relative to the reactive hot-melt adhesive element.